不同放牧强度下荒漠草原土壤养分和植被特征变化研究

以短花针茅(Stipa breviflora)草原为研究对象,设置3个放牧梯度,对不同放牧处理土壤理化性质进行了研究。结果表明:土壤容重随着放牧强度增加而显著升高(P0.05),全年重牧土壤容重上升最明显;土壤含水量随放牧强度的增加而降低,其中全年重牧下0~20cm土层下降显著(P0.05)。各放牧处理土壤有机质含量随土层深度的增加呈先下降后上升的趋势,放牧对土壤速效磷和全钾的影响不显著,全年适度放牧土壤速效钾含量最高。放牧降低了植物地上生物量,减少了凋落物的生成,地上生物量与凋落物生物量呈线性正相关关系。

Study on Changes of Soil Nutrients and Plant Community of Stipa breviflora Steppe under Different Grazing Intensities

In this study,we investigated the soil physical and chemical properties of Stipa breviflora desert grassland under different grazing intensities in Inner Mongolia,China.An experimental design with three treatments was used,including No Grazing (NG),Moderation Grazing (MG) and Heavy Grazing (HG).The results showed that the soil bulk density increased significantly with grazing intensity increasing (P＜0.05),soil bulk density increased the greatest under the heavy grazing throughout the year;while soil water content decreased with grazing intensity increasing,and soil water content in 0～ 20 cm decreased significantly under heavy grazing(P＜0.05).The content of soil organic matter decreased firstly and then increased with the increase of soil depth.Grazing had no significant effect on soil available phosphorus and total potassium while soil available potassium was the highest under moderation grazing in the whole year.Grazing reduced above ground biomass and the litter on the ground.There was a linear positive correlation between above ground biomass and litter biomass.